Sierra Space introduced a radically new concept of on-demand cargo delivery from Earth orbit. The company aims to deliver critical cargo anywhere on the planet within 90 minutes of receiving the request.
Sierra Space says the concept could allow soldiers on the battlefield or in remote areas to receive much-needed supplies in the shortest possible time since they would be far from the traditional infrastructure used to transport goods on the ground. Ghost’s orbital delivery platform can also assist rescuers in disaster-stricken areas and aid humanitarian efforts.
While several commercial launch providers, such as SpaceX and Rocket Lab, as well as the U.S. military, are discussing the possibility of using rockets to quickly deliver cargo around Earth, Sierra Space’s Ghost concept could allow payloads to land in areas where there are no special launch vehicles. or landing. This would be particularly useful for smaller payloads, thus opening up radically new opportunities for civilian supply chains in addition to military needs.
According to Sierra Space’s statement about the Ghost concept, the system will involve loading predetermined cargo such as survival kits, an inflatable boat, rations and weapons onto various “units”. These units will then be launched into orbit.
The Ghost platform can remain in orbit for up to five years before preloaded supplies are called back to Earth. After the materials are delivered, the first de-orbit engine will slow the satellite enough that Earth’s gravity will begin to pull it toward the planet’s surface. Meanwhile, the system’s thermal shield will protect the payload from future intense heating upon entering the atmosphere.
After safely entering Earth’s atmosphere, the thermal envelope will be discarded and the soft umbrella-like envelope of the system will open. A steerable rudder on the parachute can help steer the Ghost payload within 100m of the intended landing site, Sierra Space says.
Eric Dahler, Sierra Space’s vice president of orbital missions and services, said that while the Ghost system can be scaled to a variety of sizes, the “sweet spot” in terms of cost and return payload is in the 250 kg to 750 kg range. Each unit currently costs about “tens of millions” of dollars, but Dahler said Sierra Space is working to bring that cost down to “single-digit millions.”
When asked if the Ghost concept could be scaled to a size sufficient to return something as massive as the International Space Station (ISS) module, Dahler said that a similar concept could be used, but it would require slightly different design principles.
During a test campaign in February 2024, seven different test samples were dropped from a Sikorsky S-76 helicopter – some with the system’s parachute attached, others with only the system’s soft decelerator, and still others involving a “terminal” drop of only the cargo payload – from altitudes from 610 m to 1220 m.
Similar resupply concepts have been discussed for years, except for those involving point-to-point rocket launches with reusable systems, such as SpaceX’s massive Starship spacecraft.
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